Method of testing a magnetic head

Abstract

A method of testing tests a magnetic head including a read element, a write element, and a predetermined electrical circuit. A magnetic signal on a magnetic recording medium is read using the read element in a state where the read element is subjected to noise due to electrical waves and an electric field induced by applying an AC bias voltage to the electrical circuit, and the output signal outputted by the read element is evaluated.

1 . A method of testing a magnetic head including a read element, a write element, and a predetermined electrical circuit, the method comprising steps of:
 applying an AC voltage to the electrical circuit; and   evaluating an output signal of the read element in a state where the AC voltage is applied.   
   
   
       2 . A method of testing a magnetic head according to  claim 1 , wherein in the state where the AC voltage is applied to the electrical circuit, a magnetic signal is written on a magnetic recording medium by the write element, the written magnetic signal is read by the read element, and the output signal of the read element is evaluated. 
   
   
       3 . A method of testing a magnetic head according to  claim 1 , wherein a signal level of a component included in the output signal that has a same frequency as a frequency of the AC voltage is detected and the detected signal level is evaluated as a level of induced noise due to electrical waves and an electric field. 
   
   
       4 . A method of testing a magnetic head according to  claim 2 , wherein a signal level of a component included in the output signal that has a same frequency as a frequency of the AC voltage is detected and the detected signal level is evaluated as a level of induced noise due to electrical waves and an electric field. 
   
   
       5 . A method of testing a magnetic head according to  claim 1 ,
 wherein before the AC current is applied to the electrical circuit, a magnetic signal on a magnetic recording medium is read by the read element and a first normal output signal outputted by the read element is stored in a storage means,   after the output signal of the read element has been evaluated in the state where the AC voltage is applied to the electrical circuit, the magnetic signal on the magnetic recording medium is read by the read element in a state where no AC voltage is applied to the electrical circuit and a second normal output signal outputted from the read element is stored in the storage means, and   the first normal output signal and the second normal output signal stored in the storage means are compared.   
   
   
       6 . A method of testing a magnetic head according to  claim 1 ,
 wherein the electrical circuit is a heater circuit used to control a dynamic flying height.   
   
   
       7 . A method of testing a magnetic head according to  claim 5 ,
 wherein the electrical circuit is a heater circuit used to control a dynamic flying height.